Magnesia cement.



UNITED STATES PATENT OFFICE.

ROBERTO EGGENHOFFNER, OF GENOA, ITALY.

MAGNESIA CEMENT.

No Drawing.

To all whom it may concern:

Be it known that I, ROBERTO EGGEN- HOFFNER, a subject of theEmperor ofAustria-Hungary, residing at Genoa, Italy, have invented certain new anduseful Improvements in the Manufacture of Magnesia Cement, of which thefollowing is a specification.

The present invention relates to the manufacture of magnesia cement, andto the products obtained thereby.

The invention has for its basis the mixing of a certain number of partsby molecular weight of oxid of magnesium with one part by molecularweight of a chemical product obtained by the combination of one moleculeof magnesium chlorid with one molecule of magnesium oxid and onemolecule of water. This latter product will hereinafter be calledortho-oxychlorid of magnesium.

The magnesia cement constituting the present invention requires thepreceding production of the ortho-oxychlorid of magnesium, for whichproduction the cheapest .raw materials can be employed.

The principal basis of the present invention, established by theoreticaldeductions and by repeated experiments, consists in the recognition ofthe fact, that it is not the chlorid of magnesium, or its solution,which solidifies and hardens, when mixed with oxid of magnesium, butthat it is the above mentioned combination of one molecule of magnesiumchlorid with one molecule of magnesium oxid, that is to say the abovementioned ortho-oxychlorid of magnesium which solidifies with magnesiumoxid in the presence of water.

Chlorid of magnesium cannot be calcined when it is to be mixed inanhydrous condition with the oxid and to form a cement; it is howevereasy to calcine the product resulting from the combination of one molecule of chlorid and one molecule of oxid and to mix this product duringthe process of grinding, or before or aft-er the same, with the oxid .ofmagnesium in order to obtain the magnesia cement.

The magnesia cement constituting the present invention can be employedalone, or it can be mixed with wood sawdust, with detritus of minerals,with asbestos, or with I Specification of Letters Patent.

Application filed March 29,

1909. Serial No. 486,537.

any other convenient materials, such as coloring substances.

For the production of the ortho-oxychlo- Patented Aug. 15, 1911.

rid of magnesium, the principal systems that I'propose are the following(a) Bringing magnesium oxid if possible as soon as calcined and whilestill warm, into contact with anhydrous hydrochloric acid gas, thereaction being as follows This method is the least advisable because itwill not consistently yield a uniform product.

(6) Only partly calcining magnesium chlorid in the open air, so as topartially decompose it, the process being conducted with accurateweighing until the following formulae are successively obtained:16'(MgCl +6H O) (8Mg,Ol,--}-96H O) (8Mg OH Cl -{88H,O)

when by calcining pure hydrochloric acid and hydrochloric acid at 20%will be developed, that is to say:

6HC1+10 (H01: 8H O) yielding as resulting residuum 8 (Mg OCl -FH O) Thissystem will be found convenient and practicable wherever magnesiumchlorid is found native in considerable quantities.

In the great majority of cases, it will be preferable to proceedaccording to one of the three following methods, taking for a base theproduction. of ortho-oxychlorid from magnesium oxid and chlorid ofmagnesium, substituting respectively for the latter a solution ofhydrochloric acid and replacing in such cases a part of the magnesiumoxid with carbonate of magnesium.

The following formulae will be had with the respective proportionalmolecular weights:

Taking magnesium oxid (MgO) Or taking:

Magnesium oxid: 2 MgO p.w. 80. 72 A solution of hydrochloric acid Thecommon total resulting from the above treatment represents the hydratedortho-oxychlorid having the formula M oo1 +1111,o.

In order to obtain this product according to the above treatment it willbe necessary to keep the mixture fn continuous. movement until it willbe uniformly solidified, at times heating the mixture in order to hastenthe combination, whereby the oxid depositing on the bottom shall beprevented from combiningv with a minor quantity of chlorid leaving freea part of the solution. At all events, either the solution of thechlorid or of the acid may be more or less strong; the strength needonly be taken into account inthe calcining; it will also be necessary totake-intoai-account the impurities contained in the oxid 'or carbonateof magnesium.-

The costof production in these cases is very slight. By calciningtherefore the hydrated ortho-oxychlorid pure ortho-oxychlorid will beobtained as follows:

' Hydrated orthoo xychlorid,

-Mg OCl 11l-I O p.w. 333. 84 Less water, 10H O 180. 20

R e m a in s pure ortho-oxychlorid,

Mg OCl' +I-I O 153. 64

cal equations.

. invention especially that called Now that I have described theprocesses for the'production of the ortho-oxychlorid of magnesium, Iwill now-proceed to give the formulae of two kinds -of magnesia cement.These are called litosilo magnesia cement and orthochlor magnesiacement. If 153.64 parts of pure ortho-oxychlorid of magnesium are mixedwith 7 40.36: 82.52 parts of ma nesium oxid, 436.16 parts of anhydrouslitosilo magnesia cement are obtained, to which, it may be added informing the paste, at the maximum, 26 18.02:468.53 parts of water. If,on the contrary, 153.64 parts of pure orthooxychlorid are mixed with 340.36=121.08 parts of magnesium oxid, 274.72 parts of anhydrousorthoehlor magnesia cement are obtained to which maybe added, at themaximum, 18 18.02:324.36 parts of water.

We have dealt hereabove with numbers proportional tothe molecularweight, in order to facilitate the working of the chemi- The orthochloras compared with litosilo is cheaper, besides I which it presents thefurther advantages of being less dense, and when agglomerated 'withsawdust and the like it yields a lighter and more homogeneous product,which is also more resisting and flexible, and absorbs sound better.

The magnesia cement according to the present invention may be placed onthe market in a state of purity or mixed with wood or with asbestos andother mineral detritus.

The cements produced according to the above mentioned formulae may' becalled anhydrous litosilo and anhydrous orthochlor according to theproportion of magnesium oxid employed, as was stated above. Thesecements may be used immediately after their manufacture or theoxychlorid and the. other ingredient may be preserved dry for a longtime and transported when by mixing them with water only, a product isobtained ready to be spread and made use .of, identical with thatobtained when the manufacture is complete atone operation.

When the magnesia cement of the resent orthochlor is mixed with mineraldetritus or alone, it may serve for a cement in lining elsterns,terraces, reinforced cement structhose works which are subject to greattures such as balconies and the like; mixed shocks such as the blocks ofcement pro- -which opposes a maximum of resistance both to penetrationand to flexion. This latter characteristic permits of its use (alwayswhen strengthened internally by expanded metal bars or rods) also intheconstruction of decks directly on the girders, thus partially orentirely substituting wood and iron. 7

Whatever mixtures may be obtained according to the aforesaidindications, the relative cements may be placed on the market with orwithout the addition of a definite quantity of Wood sawdust, coloringearths, asbestos, mineral detritus, and the like, according to therequirements of the uses to which they are to be put; and each of theaforesaid products will require a different quantity necessary to formpaste of the required consisten I claim: 1 1

1. Magnesia cement consisting of a mixture containing a: parts ofmolecular weight of magnesium oxid and one part of molecular weight ofpure magnesium ortho-oxychlorid, according to the formula:

as being a variable number.

2. Magnesia cement consisting of a mixture containing aparts ofmolecular weight of magnesium oxid and one part of molecular weight of amagnesium oxychlorid which latter is formed by the combination of onemolecule of magnesium chlorid with one molecule of magnesium oxid andone molecule'of water according to the formula:

Mg,OCl,.H O, a? bei a variable number.

gnesia cement consisting of a mixture containing 7 parts of molecularweight of magnesium oxid and one part of molecular weight of puremagnesium orthoeoxyname in this specification. in the prese ceof twowitnesses.

ROBERTO 1 Witnesses:

P10 BINALVINIL, ANGELQBRAGUM.

